Patent US3678727A successfully refreshed from Google Patents.
US3678727A
Expired / Lapsed
US
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Stretch-draw tubing process
Assignee: Individual
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Filing: 1970-08-27
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Granted: 1972-07-25
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Expires: 1990-08-27
Abstract
Abstract Metallic tubing is drawn under tri-axial stress. A tube which has the capability of cold work is used as a starting material. The tube is stretched longitudinally under cold working conditions without restraint against reduction in diameter and in cross section into the plastic range but below the point of necking to reduce its diameter. Then the tube is drawn with tools which subject it to force inwardly on two axes at right angles to the longitudinal axis and at right angles to one another under cold working conditions into the plastic range. The cold worked condition of the tube is retained during the stretching and drawing.
Inventors
- 👤 Robert G Jackson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:33
CPC Classifications
B; B21; B21C; B21C1/00; B21C1/16; B21C1/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
100 words
The process of drawing metallic tubing, starting with metallic tubing capable of undergoing cold work, which comprises stretching the tubing longitudinally under cold working conditions without restraint against reduction in diameter into the plastic range but below the point of necking to reduce the diameter and wall, and then after relieving the tension drawing the tubing with tools which subject it to force on two axes at right angles to the longitudinal axis and at right angles to one another under cold working conditions into the plastic range, the cold worked condition of the tubing being retained between the operations.
Claim 2
Dependent Claim
100 words
The process of drawing metallic tubing, starting with metallic tubing capable of undergoing cold work, which comprises stretching the tubing longitudinally under cold working conditions without restraint against reduction in diameter into the plastic range but below the point of necking to reduce the diameter and wall, and then after relieving the tension drawing the tubing with tools which subject it to force on two axes at right angles to the longitudinal axis and at right angles to one another under cold working conditions into the plastic range, the cold worked condition of the tubing being retained between the operations.
Claim 3
Dependent Claim
30 words
The process of claim 1, in which the drawing of the tubing with tools is accomplished by compression of the tube wall in the radial direction, and compressive hoop stress.
Claim 4
Dependent Claim
30 words
The process of claim 1, in which the drawing of the tubing with tools is accomplished by tension of the tube wall in the radial direction, and compressive hoop stress.
Claim 5
Dependent Claim
31 words
The process of claim 1, in which the drawing of the tubing with tools is accomplished by compression of the tube wall in the hoop stress direction and compressive radial stress.
Claim 6
Dependent Claim
31 words
The process of claim 1, in which the drawing of the tubing with tools is accomplished by tension of the tube wall in the hoop stress direction and compressive radial stress.
References Cited (Backward Citations)
US3469425A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |